My old 1000SP project returns

[Michael Moore]

Back in December 1993 I bought a rough, lightly crashed/scorched 1979 Guzzi 1000SP.  I took it apart and started accumulating parts and sending work out (ported big valve heads, Megacycle cam, Carrillo rods, Sudco FCR41 kit, later Guzzi fine spline clutch components, alloy timing gears, new u-joint/drive shaft assembly, etc), and finally about 19 years later, after languishing in storage, I sold it to a friend.  He sent the trans and final drive to an East Coast Guzzi racer (Charley Cole) who specialized in working on those (taking the business and all tools/tech over from the US Raceco when they closed)  and had them gone through.  He bought some other stuff (I just noticed a sump spacer with an external oil filter in the photos below) and assembled the wheels with the flangeless WM4/WM5 Akront rims I'd purchased.

Steve ran into some stumbling blocks and lost interest and today the Guzzi came back to my garage, nearly 28 years after I first purchased it.  It is funny how the marbles can be swapped in circles like that.

When I started I was actively racing and wanting to build a semi-cafe racer hotrod.  Now, I'm more interested in a solo rider sport tourer (with pumped engine). 

I've got a couple of waist-high stacks of tubs filled with parts that I need to inventory.  After cleaning up a set of stock small-valve heads from one of those boxes I'll get port molds from them as well as the hotrod heads that need some exhaust manifold fastener rework, just in case I have to replicate the ported heads.

Nothing will happen quickly, but  hopefully something may actually happen -- some day.  But I've gotten to where having something to fiddle with and do research/planning/CAD etc are entertaining enough to satisfy me even if riding isn't taking place.

From 1993:




Today:








cheers,
Michael

[Motorad64]

Looking forward to seeing it come together!

[Michael Moore]

Me too!  Maybe I can get it done before 30 years are up.   

[Turin]

lok forward to watching the progress !

[Groover]

Great story, and sounds like a nice project in the works.

[nmroadrunner]

Me too!  Maybe I can get it done before 30 years are up.   

Yes, you need to get going on this before I'm too old to ride it! 

[Michael Moore]

I wanted to start off with something fun on the SP, so I gathered up some port molds I had on hand and also made molds from a couple of Guzzi heads.

The molds I already had  were given to me by the late Ken Augustine (Kinetic Analysis) a very well known cylinder head guy (he did the heads for the Butler and Smith BMW Superbikes back in the day, and for many top riders and also factories).  Those I'll show are for a Yamaha TT500 with stock valves (47intake and 39 exhaust) and intake/exhaust manifold locations.  Ken told me that they had very impressive flow numbers.  I road raced a TT500 special in a Kenny Roberts frame for 6 years and Ken knew that I liked the motors. Ken's molds include the combustion chamber.

In the middle are heads by Craig Hanson that I had him do for the SP.  Craig did a lot of head/dyno development work over the years and built the heads on my Honda and Laverda vintage road racers.  These have Kibblewhite 44/37 valves.

The remaining set are from a stock head (I'd picked up an extra set) with 41/36 valves.

These are the raw scans of the port molds without any post-processing/smoothing of flaws where the molding might not have gone quite right, or had small tears develop when being removed from the heads.

The Guzzi ports are pretty crude.  It doesn't surprise me that stock head bikes often don't respond well to bolt on mods like big carbs etc.

Craig's ports have welded-up exhaust port floors and epoxy filler in the floor of the intake port.  You'll note he's added some offset for swirl in the intake.

Ken's TT500 ports are pretty cool, and show what can be done by someone who was a top-level porter for many decades.  The Yamaha is a 500 with 87x84mm bore/stroke, and somewhat less included valve angle than the Guzzi.  My SP with Gilardoni kit is 90x78.  The Yamaha intake would break out into the stud tunnels and is 10mm wider than Craig's intake.

Once I've dug out my flow bench and refreshed my memory on how to use it (and make a valve-opening fixture for the heads) I'll put the stock and modified Guzzi heads on it to get some comparison numbers.

cheers,
Michael

[Rick4003]

Hi Michael,

Very cool story and thank you for posting the port info, that is right up my ally!

I too have a plan to do some work on the ports and it is very interesting to see how others have done it, specially the ones who have been at the top of the came for decades!

I am looking very much forward to following along!

-Ulrik

[Michael Moore]

I'm glad you found it interesting, I wasn't sure if it was too technical/esoteric to be of much interest to people.  I'll post more info as I accumulate it.

[Rick4003]

I am not sure how many would find it interesting (or how many people that actually drift over in this section of the forum) but I find that stuff very interesting. But if you're the type who believe that the Guzzi Engineers knew exactly what was best and that it shouldn't be messed with then maybe it is not such a interesting side of the forum here.

I will be looking much forward to updates on the build and don't feel you need to hold back with the details :) 

[Michael Moore]

But if you're the type who believe that the Guzzi BMW/Harley-Davidson Engineers knew exactly what was best and that it shouldn't be messed with

Fixed that for you.   

The few Guzzi people I've known have generally been at least mechanically inclined, and many have been interested in engine technology/gear-head stuff.  Perhaps that was just something from the old days, like how if you wanted to go road racing you generally had to build the bike yourself.  Now people walk into their dealership and buy the latest/greatest sport bike and have it safety wired and they're ready to race.  I've always found the tech stuff interesting, which is why I ended up designing and building frames for some of my race bikes.

On the other hand, old (and often not too wonderful) bikes/cars have more bad design features that give a person something to fiddle with.  There's no sense fiddling with a modern bike that in stock form goes 500% faster than I'll ever be able to ride it.

[Pescatore]

Hey Michael, I found links with your name related to drag racing.  Do we have a champion on this forum????  Wow!

I appreciate any details.  Some of this stuff is over my head, so I turn to Google University.
It is tough to follow, considering the number of threads constantly churning on this forum.
Many times I don't have the time to do that, so I prefer more details.
Thanks,
Pescatore

[Michael Moore]

I did a few runs at Wednesday night drags with my 500 Yamaha and the 650 Cagiva, but that's all.  My competition activities were in road racing, motocross and observed trials.  Generally, I've been a good Novice level rider, or an OK mid-pack intermediate, with trophies happening in small classes when no one fast shows up, or the fast person jumps the start/crashes/breaks.      But not doing those things that make you lose is part of racing, so I didn't give those trophies back!

cheers,
Michael

[Michael Moore]

Are damaged valve adjuster screw threads a common problem?

I've looked at two rocker arms from my 1978/79 1000SP so far (the others haven't surfaced).  Both of them have a similar "failure mode".    The 11mm-hex M8x1.0 jam nut can be loosened and backed off the pushrod adjuster screw without problem.  The screw can then be screwed in (ball end closer to the rocker arm) without problem.

But trying to remove the screw sees it move a bit and then jam up solid.  This happened on both screws.  I looked at the screws with some magnification and when rotating them the screws don't show obvious signs of being bent, and the threads don't appear damaged.

My guess is that a prior owner cranked down on the jam nuts pretty hard, and there's some minor distortion on the threads "above" (the side with the jam nut) the rocker arm.  It is probably over a short distance so the thin nut doesn't have any issues going over those threads, but once they are in the rocker arm which may also have a tighter clearance than the jam not, things get unhappy and stop moving.

I've cut one screw in half roughly where the jam nut was, and the portion with the ball end was then able to be unscrewed without jamming.

I'll be interested to see if the other two screws are the same way.  Is this kind of issue something that is relatively common where someone may have gotten a bit eager on making sure the jam nut didn't come loose?

thanks,
Michael

[Michael Moore]

I found the box with the instruments, and the odometer is showing 46122 miles.  Guzzis may be fairly long lived, but I suspect that means I need to look at all "normal wear" items and expect to find some that are past their service life.

[Canuck750]

Very interesting information on porting! I would like to learn a wee bit about that one day, the science is way above my pay grade! Great back story to this build, and thanks for sharing your race history. 

Jim

[Canuck750]

I am not sure how many would find it interesting (or how many people that actually drift over in this section of the forum) but I find that stuff very interesting.

Sadly those that don’t check out this side of the forum are missing the gold. 

[Rick4003]

Sadly those that don’t check out this side of the forum are missing the gold. 

I fully agree on that 

[huub]

Hi Michael,

great writeup,
the issue with the set screws is known, as you suspected somebody overtightened the jam nuts.
guzzi's are easy to work on, and pretty tolerant to mechanical abuse , they will run whatever you do to them.
so every on used guzzi i had  i end up discovering loads of interesting bodges from the previous owners...

[Michael Moore]

I've gotten a lot of new parts and Guzzi tools in, but I'm still waiting on a few critical engine parts to show up.  I've done a quick "get the bulk of the grime off" cleaning of the crankcase and have been doing my usual preassembly fettling.  There are spots where the 46K mile aluminum picked up some gouges that left sticky-outy bits, and other spots where there's a bit of casting/machining flash that I'll remove.  It is easy to find the parts to work on with the file/scraper/small rotary burr, just rub your hand across the part and where blood is left behind you know there's something that needs to be dealt with.   











New parts aren't immune from this inspection/fettling, the new main bearings are nicely machined but weren't completely deburred afterwards.









To pass the time I scanned the crankcase, due to the line of sight limitations of the scanner even with 250 scans there are still a few holes where the scanner couldn't get a look at the case:





The thumbnail photos aren't the full area so be sure to click on them for the larger version.

Slow progress, but progress none the less.

cheers,
Michael

[Chuck in Indiana]

That scan of the crankcase is amazing. Modern tech can do some wonderful things..

Steve ran into some stumbling blocks and lost interest and today the Guzzi came back to my garage, nearly 28 years after I first purchased it.  It is funny how the marbles can be swapped in circles like that.

Speaking of marbles.. I once had a 1000SP out in California that had electrical issues. (Imagine that..) It needed a new harness, but I didn't have time to do that on my infrequent vacations, so sold it to Eldo Jon with the warning that it needed electrical work. The last I knew of it, it had moved to Arizona.
Years pass.
Pete and I rode to the Oregon nationals, and I set up my tent. Went to register, and when I came back there was an old 1000SP right beside my tent with it's tail in the air and somebody working on it. Thought, "funny.. that is the same color as my old SP." It was Greg Fields working on it, and it was my old SP. (!) A guy from Italy had bought it and left it at Moto International to use for vacations..

[Frenchfrog]

I'm glad you found it interesting, I wasn't sure if it was too technical/esoteric to be of much interest to people.  I'll post more info as I accumulate it.

Very much of interest Michael...this is about the only reason I visit Wild !!

[El Vikingo Tropical]

Very interesting reading indeed, thanks for sharing!